Plate-holder for printing-presses



H. G. TURNER.

PLATE HOLDER FOR PRINTING PRESSES. APPLICATION HLED JULY 17, 1920.

LQQQ QQQ Patented Mar. 1, 1921.

fm m r HARRY G. TURNER, OF CHICAGO, ILLINDIS.

PLATE-HOLDER FOR PRINTING-PRESSES.

Specification of Letters Patent.

Patented Mar. 1, 1921.

Application filed July 17, 1920. Serial No. 396,978.

To all whom it may concern:

Be it known that I, HARRY Gr. TURNER, a citizen of the United States ofAmerica, and a resident of Chicago county of Cook, and State ofIllinois, have invented certain new and useful Improvements inPlate-Holders for Printing-Presses, of which the following is aspecification.

The purposes of this invention are to provide a practical plate holderfor plate printing presses of the general type known as roller,embossing or die presses designed to make impressions from engravedplates. It is customary in plate presses to secure the plate to the bedof the press by soap or paste on an intervening piece of cardboard. Suchmanner of mounting the plate on the bed of the press sometimes resultsin slight creeping of the plate along the bed. Plate holders are oftennot practicable for this class of work, due to time required inadjustment and the fact that the parts thereof are apt to tear the wiperof the plate-wiping mechanism. Further, the plates are comparativelythin and should be raised from the plate holder or bed of the press inorder that the inking and wiping devices engage the surface. The. plateholder should also provide a solid back at all points of the plate.

With these objects in View, the invention comprises a pair ofrectangular blocks which are slidable with respect to each other toaccommodate plates of diiferent lengths, and each block at one endcarries a tooth-shaped member for entering notches which have been cutin the edges of the plate, preferably along the center line of theengraving. The two blocks when set as desired are secured againstdisplacement by means of a clamp or chuck commonly employed in thepluming art.

The objects of the invention are accomplished by the device shown in theaccompanying drawings, in which- Figure 1 is a perspective view of aplate holder and clamp constructed according to this invention.

Fig. 2 is a perspective view of one of the toothed plate-engagingelements.

Fig. 3 shows in perspective a plate notched as required for beingengaged and centered by the plate holder." 1

The drawingsshow a chuck consisting of a frame structurel and a pair ofclamping elements 2 and 3, "oneof which is adjustable toward the otherby means of a nut thereon coacting with a threaded bolt, the head ofwhich is indicated at 4:. This being an ordinary form of chuck, detailedillustration thereof is omitted.

The plate holder to which the invention relates consists of a pair ofrectangular blocks 5 and 6 located between the clamplng elements 2 and 3and adjustable with respect to each other transversely of the chuck. Thechuck provides a solid bearing for the blocks 5 and 6 and the latter inturn provide a bearing at all points for the engraved plate 7. The platebefore being placed upon the plate holder is notched, preferably alongthe center line of the engraving, as indicated at 8. These notches maybe quickly out in the edges of the plate by a file, such as a triangularfile or other which corresponds in form to the shape of teeth 9 on theplate-securing members 10 and 11. The member 10 is secured to block 5and the member 11 is secured to the block 6 by means of screws 12. Oneof the members 10 or 11 is properly mounted on its block to affordresilient means for engaging the notch in the edge of the plate, andwhich may be tightened against the plate by means of a screw 13 havingthreaded engagement with an aperture in the end of the block upon whichit is mounted.

The construction described affords a simple means for securing the plateagainst displacement provides a firm bearing for the plate and issuitable for properly clamping a very thin plate without any part of theclamping means projecting above the plate or interfering with the actionof the wiper which is usually given a sweeping circular motion over, theplate.

In clamping a plate by means of this plate holder, the plate is firstnotched at its side edges. The plate is then placed upon the blocks 5and 6 which are then slid toward each other along their contacting edgesuntil the toothed elements 10 and 11 engage the notches in the edges ofthe plate. The blocks 5 and 6 are firmly held in this position while theclamping screw is turned to clamp the blocks between the clampingmembers 2 and 3. The plate is then further tightened between the toothedengaging means by an adjustment of screw 13.

Although but one specific embodiment of this invention has been hereinshown and described, it will be understood that numerous details of theconstruction shown may be altered or omitted without departing from thespirit of this invention as defined by the following claims.

I claim:

1. A plate holder of the class described, comprising a pair of blocksslidable with respect to each other along coacting edges, clamping meansfor clamping the blocks togetherin set position, and a tooth carried byeach block for engaging the edges of a plate resting on the block.

2 A plate holder of the class described, comprising a pair of blocksslidahle with respect to each other along coacting edges, clamping meansfor clamping the blocks together in set position, and a tooth on one ofsaid blocks for engaging the edge of a plate resting on the blocks.

'3. In an device of the class described,

the combination with a printing plate having notches cut in its edges,01 means for securing said plate against displacement in a printingpress, comprising a clamp coacting with a pair of blocks slidablymounted on said clamp and each carrying a tooth for engaging the notchesin said plate.

4. In a device of the class described, the combination with a printingplate having notches cut in its edges, of means for securing said plateagainst displacement in a printing press, comprising a clamp coactingwith a pair of blocks slidahly mounted on said clamp and each carryingtooth for engaging the notches in said plate, and one of which teeth isadjnstably mounted on its block.

Signed at Chi 'ago this 15th day of July,

HARRY G. TURNER.

